The invention relates to an arrangement for a functional support of a counter-pressure plate for a shaft-like surgical stapling instrument, particularly a laparoscope VBG (Vertical Band Gastroplastic) according to Mason, wherein a hole has to be punched into the front and the rear stomach walls which is done using a circular stapler.
With such laparoscopic surgeries, a stapler provided with a thorn is pushed from the front toward the back or vice-versa through the front and rear stomach walls and then connected to a counter pressure plate. By way of this hole, the stomach fundus is separated and the exit is surrounded by a band so that it cannot expand. Because of large difficulties to join the counter pressure plate behind the stomach to the thorn of the stapler and the danger of injuring directly adjacent organs such as the pancreas or large vessels, this surgery is generally performed in an open surgical procedure. So far, it is performed laparoscopically only in a few centers worldwide.
With the surgical stapling instruments known so far from DE OS 3 300 768 and DE PS 3 301 713 for the interconnection of two organ walls, the connection between the thorn and the counter pressure plate depends essentially on the experience and the sense of touch of the surgeon and is possible reliably only by open surgery.
It is the object of the invention to provide for the laparoscopically experienced surgeon an appartus for a functionally correct support of a counter pressure plate for a rod-like surgical clamp suturing instrument like an aiming device which facilitates a simple and safe connection by the clamp suturing instrument or, respectively, the circular stapler and the counter pressure plate.
In arrangement for supporting a counter pressure plate of a shaft-like surgical clamp suturing instrument for establishing a circular seam, a shaft-like clamp suturing instrument having at its distal end a support and guide structure and a one-piece support structure axially movably supported on the support and guide structure and having a support portion extending normal to the shaft section and releasable engaging a back-pressure plate in a position where the back-pressure plate is in axial alignment with the shaft section.
With the arrangement according to the invention, the laparoscopically experienced surgeon receives a safe auxiliary device for a reliable interconnection of a stapler and a counter pressure plate behind the stomach. At the same time, the arrangement according to the invention provides for a design and construction, which prevents injuries to surrounding organs and vessels.
The device can be easily attached to shaft sections of circular staplers or clamp suturing instruments and preferably consists only of single-part support member which, because of its shape, can be easily inserted behind the stomach wall and can also be properly adjusted for an accurate alignment of the counter-pressure plate for the intended connection because of its adjustable mounting on the shaft section and the removable support member for the counter pressure plate.
In a preferred embodiment of the invention the support member has a clasp-like shape wherein the engagement section for the counter pressure plate is provided at a widened end. The clasp-like shape combines the advantages of a rounded profile structure, which provides for small chances of injuries and those of simple manufacturing.
Preferably, the support section for the counter pressure plate comprises two semi-circular sections including an at least partially form fitting reception area for the outer contour of the counter pressure plate. These measures provide for safe positioning of the counter pressure plate for the intended connection with the thorn, which is extendable from the stapler. Preferably, the semicircular sections can be spread apart against the force of a spring structure which force preferably also provides for engagement of the counter pressure plate in the support section in order to ensure, together with the form fitting engagement, the safe retaining of the counter pressure plate.
In a preferred embodiment of the invention, the support member includes a sled-like mounting section which can be attached to a complementary profile section of a support and guide structure mounted on a distal end of the clamp suturing instrument such that it is movable between at least two engagement positions and is removable from the support and guide structure. Such an arrangement permits the support structure to be moved behind the stomach while in a first engagement position in which it is located further removed from the distal end of the clamp suturing instrument. After reaching the predetermined operating position, the support structure can be moved closer to the distal end of the thorn of the stapler to which it is to be coupled. After the pressure plate and the thorn have been joined, the stomach walls have been moved together and the holes have been punched, the support member can be removed in a simple manner from the counter pressure plate by backsliding of the support structure. Then the support member can be removed from the support and guide structure and deposited for removal from the operation area.
The movable mounting section of the support member preferably includes two parallel clamping legs and horizontal transverse sections. Preferably, the movable section of the mounting member is provided with at least tow disengageable locking members for securing the rest positions formed on the support and guide structure. The locking members are preferably self-engaging members such as spring-loaded balls which are received in corresponding recesses formed on the support and guide structure.
For the attachment of the support and guide structure, preferably a two-part mounting sleeve, which can easily be mounted, is provided. It includes a shot mounting section and a profiled section for the mounting section. The two mounting sleeve parts include sections, which are in engagement with each other.
For the release and the movement of the mounting part, at least one yoke-like handling structure is provided.
To facilitate the removal of the support member, in accordance with another embodiment of the invention, the support member is provided, at its end opposite the engagement section, with a structure for the attachment of a pull member.
In accordance with still another embodiment of the invention, a surgical clamping device for forming circular sutures is provided. It comprises a one-piece support member with a sidewardly projecting portion, which forms at its end an engagement portion for the releasable engagement of the counter pressure plate. A guide structure, which is removably mounted on the device shaft, is provided for the positioning of the counter pressure plate. Particularly the coupling of the counter pressure plate and the clamp suturing instrument by means of a guide structure ensures that the counter-pressure plate is moved toward the pull member or, respectively, the clamp magazine in its proper position and that a proper adaptation of the counter pressure plate is provided with the pull member. The releasable connection of the guide structure to the device shaft facilitates the separate introduction of the guide structure and the device shaft of the clamp-suturing instrument by way of a trocar. The guide structure and the device shaft are than interconnected within the belly of the patient. The separation of the equipment shaft and the guide structure is necessary since the diameter of the trocar is generally only slightly greater than the diameter of the clamp magazine so that the insertion of the device shaft with the guide structure attached thereto is impossible for most applications.
In a preferred embodiment, the guide structure according to the invention comprises a guide means which may be coupled to the device shaft by a coupling, a guide tube which is axially movably supported in the guide means and a support structure arranged at one end of the guide tube for receiving the counter pressure plate. The coupling for the interconnection of the guide structure with the device shaft comprises a mounting portion which surrounds the device shaft and which is preferably a clamping sleeve, and a coupling plate for the connection of the guide means to the mounting portion. To facilitate the insertion of the device shaft into the belly of the patient through the trocar the mounting part and the coupling plate of the coupling may be pivotally interconnected by means of two parallelogram-like lever pairs such that the coupling plate can be pivoted toward the device shaft whereby the circumference of the clamp suturing instrument is reduced. To this end, preferably the surface contour of the coupling plate facing the device shaft is adapted to the surface contour of the device shaft such that the coupling plate abuts the device shaft in a form-fitting manner in the collapsed insert position.
The lever pairs of the coupling can be pivoted by means of a linkage or a tackle, which is connected directly to the coupling plate and which includes a handle and is supported on the device shaft or respectively, the operating handle of the clamp suturing instrument. If a tackle is used, it is advantageous if furthermore at least one return spring is provided for the return of the coupling plate from the insertion position in which the coupling plate is pivoted onto the device shaft to the extended operating position. The return spring is connected with one end either to the coupling plate or at least one lever pair. The other end is mounted to a mounting structure.
In another preferred embodiment, the coupling is returned to an operating position by means of two parallel return springs which are connected with one end to the connecting plate and with the opposite end to the mounting structure.
In a further embodiment, half of the coupling is connected to the device shaft and the support for the counter pressure plate is connected to the guide tube by way of lever pairs such that the pivoting of the lever pair results in an orientation of the counter pressure plate which is co-axial with the device plate.
In connection herewith, the lever pair assigned to the coupling may be two parallelogram levers which, in the axial direction of the device are disposed on top of one another and between the device shaft and the associated coupling half of the coupling, whereas the lever pair assigned to the support structure for the counter pressure plate is arranged at the end of the guide tube wherein the connecting arm axes at the guide tube are disposed on top of one another in the longitudinal direction of the guide tube.
To facilitate the insertion of the guide structure into the trocar, the counter pressure plate can be pivoted together with the support structure thereof by means of a lever pair connected to the support structure from an operating position in which it extends parallel to the axis of the guide tube to an insert position in which it is disposed co-axially with the guide tube, wherein a coupling pin arranged concentrically on the counter pressure plate is disposed between the lever pair.
In order to permit actuation of the lever pair assigned to the support of the counter pressure plate when the guide structure is inserted in the trocar, an operating linkage is disposed in the guide tube, which, with one end, is connected to one of parallelogram levers of the support for the counter pressure plate and, with the other end, to a hand operating structure for the manual operation.
To avoid an unintended movement of the support structure for the counter pressure plate out of the operating position spring means are provided on the guide and the adjustment linkage, which bias the adjustment linkage in a position corresponding to the operating position of the counter-pressure plate so that the counter-pressure plate can be removed out of the operating position only against this spring force.
In order to ensure proper operation of the guide structure, a connection with accurate relative positions of the guide structure and the coupling plate are required. In order to ensure that the parts to be joined are accurately positioned the guide structure includes a centering pin which cooperates with a correspondingly-shaped centering bore in the connecting plate.
The guide structure is then fixed to the coupling plate by means of spring clamps or by resilient engagement tongues disposed on the guide structure, which are received in corresponding engagement recesses of the coupling plate.
In order to ensure a safe connection of the coupling part of the guide structure, the front side of the guide structure is provided with an angled support member which projects beyond the contour of the guide structure. The support member is received in a correspondingly shaped recess of the coupling plate and accommodates the forces resulting from the engagement tongue or engagement spring mounting arrangement.
Alternately, a guide panel which extends beyond the outer contour of the guide structure may be arranged at two opposite surfaces of the guide sleeve which guide panels cooperates with a complementary guide surface at the connecting plate. The spring tongues or spring clamps are so arranged at the guide structure that the effective directions of the guide panels and the retaining springs are displaced by 90xc2x0. In connection with this spatial arrangement of retaining clamps and guide panels, it has also been found to be advantageous to utilize a U-shaped spring clamp and about V-shaped bent-over end sections at the ends of the spring arms.
In order to provide for a secure axial locking of the guide tube within the guide structure, the guide structure includes a spring-loaded engagement means, which is spring biased in radial direction and which cooperates with corresponding engagement recesses or marks on the shaft of the support structure. Preferably, the engagement means consists of an engagement ball, which is disposed in a radial bore in the guide and is engaged by a compression spring.
The guide tube is prevented from rotation by providing the guide tube with a shape other circular and the guide structure surrounds the guide tube in a form-fitting relationship. Preferably, the guide tube has an oval cross-section.
The support structure for the counter pressure plate is essentially annular and includes two radial clamping jaws which are connected by two shaft sections to the lever pairs so as to be pivotable about an axis which extends parallel to the pivot axis of the lever pairs.
Below, the invention will be described in greater detail in the reference to the accompanying drawings.